Open AccessThe effective acceleration of plasma outflow in the paraboloidal magnetic field
Author(s) -
Beskin V. S.,
Nokhrina E. E.
Publication year - 2006
Publication title -
monthly notices of the royal astronomical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.058
H-Index - 383
eISSN - 1365-2966
pISSN - 0035-8711
DOI - 10.1111/j.1365-2966.2006.09957.x
Subject(s) - physics , lorentz factor , magnetohydrodynamics , magnetic field , lorentz force , classical mechanics , poynting vector , quantum electrodynamics , mechanics , computational physics , lorentz transformation , quantum mechanics
The problem of the efficiency of particle acceleration for a paraboloidal poloidal magnetic field is considered within the approach of steady axisymmetric magnetohydrodynamic (MHD) flow. For the large Michel magnetization parameter σ it is possible to linearize the stream equation near the force‐free solution and to solve the problem self‐consistently as was done by Beskin, Kuznetsova & Rafikov for a monopole magnetic field. It is shown that, on the fast magnetosonic surface (FMS), the particle Lorentz factor γ does not exceed the standard value σ 1/3 . On the other hand, in the supersonic region, the Lorentz factor grows with the distance z from the equatorial plane as γ≈ ( z / R L ) 1/2 up to the distance z ≈σ 2 R L , where R L = c /Ω F is the radius of the light cylinder. Thus, the maximal Lorentz factor is γ max ≈σ , which corresponds to almost the full conversion of the Poynting energy flux into the particle kinetic one.